I just had an engine swap done and on occasion I have a really high pitch whistling noise (kind of like a tea kettle) when I release the gas pedal. When I press down on the gas pedal again the noise is gone. It only happens when it is released.

Maybe a vacuum leak?

I have no idea what the noise is. Anyone know?

Thanks.

id say vaccum leak to
look under the hodd and rev up the motor and try and see if u can hear where its comin from

Has to be the turbo

cat under dash board tail suck in linkage

haha funny stuff guys, but seriously. I need some help. I've already put a lot into her with the engine swap and everything. I just want to see if anyone has some suggestions?

How do you find a vaccum leak?

Do you have a cold air intake or a throttle body spacer? Those two are known to have a whistling noise.

easiest way I know of to find a vacuum leak is take another piece of hose, say 3/8's or so, put one end to your ear and start moving the other end around and along the vacuum lines. You'll hear it when you find the leak.

No I don't have them.

Ok thanks.

So I was driving around today and the high pitch noise, which is seriously deafening, started going off and I pulled into a parking lot to try and listen to where it is coming from. I popped the hood and it is so loud that you can not decipher where it is coming from.

It's gotta be a leaking vaccum line. When I release the gas pedal I can sometimes here like a quick suction sound. It does sound like it is coming from the drivers side though.

Any other ideas guys? This noise is killing me and everyone else around me LOL!

Is it an alarm? Did you steal this jeep? Sounds like you did! JK you can't narrow it down? Like say it is for sure the upper,lower,driver,passenger side?

MixterXJ you're not alone. I have a 2001 XJ, and mine is doing the same thing currently, it really sucks! I too notice mine, usually at low speeds, definitely when the gas pedal is released. It stops when I accelerate, and for the first time it actually continued long enough for me to throw it into park, jump out, pop the hood, ............then it quit. Nice. I'm in you're boat though, and awaiting some help as well in terms of a solution.

check the gasket around the throttle body. it is just a thick piece of cardboard. mine did this and i had a crack in mine

Thanks for the info guys.

I'm having the guys that did the swap check it out tomorrow and see what they find. I will keep you guys updated.

Could it be the vaccume line comin threw the fire wall? Or maybe a pully? friends dodge had one of the bearings for is pully go bad and it made a high pitched squealing noise, so maybe that? Just an idea.